Recently I have tried to do a P2V of a Windows Server 2008 SP2 x64 Server: a physical server to a Hyper-V server. To achieve my goal, I used the Microsoft Virtual Machine Converter 3.1 utility.

All was fine during the configuration phase until I got to the actual migration part. The Wizard was failing at the drive snapshot phase with the following error:

MVMC is unable to create a volume snapshot set on SERVER. Error code: 0x809933BB.

After some digging and some time spent in the Application Event Log, I saw there was a correlation between the time I was trying to do the snapshot and an event called CAPI2 with and ID of 513.

The body of the error was as follows:

Cryptographic Services failed while processing the OnIdentity() call in the System Writer Object.

AddCoreCsiFiles : BeginFileEnumeration() failed.

System Error:
Access is denied.

Now my first hint was the Access Denied line. Access denied to what? After doing some research, I realized it might be linked to the FileMaps folder.

So here’s what I did to fix it.

First step is to go to the C:\Windows\winsxs\FileMaps folder and open the Security dialog box.

Afterwards, we go to the Advanced tab and take ownership of the folder, since the current owner is TrustedInstaller. Also, be sure to check out my detailed post on how to delete files that are protected by TrustedInstaller.

Now we give full permissions to the Administrators group on that specific folder. The next time I tried the migration, it worked perfectly. Hope this helps anyone who gets stuck using VSS and ends up with this type of error. Enjoy!